Explosive projectile



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FILED EXPLOSI APPLICATION Patented Aug. 4, 1914.

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JOHN B. SEMPLE, OF SEWICKLEY. PENNSYLVANIA.

EXPLOSIVE PEOJEGIILE.

Specification of Letters Patent.

Patented Au 4, 1914'.

Application filed January 14, 1914. Serial No. 811,969.

To allwhom it may concern Be it known that I, JoHnB. SEMPLE, r esiding at Sewickley, in the county of Allegheny and State of Pennsylvania, a citi- 5- zen of the United States, have invented or discovered certain new and useful Improvoments in Explosive Projectiles, of which improvements the following is a specification.

My invention relates to explosive projectiles and consists in the composition and arrangement of the burster charge.

The invention is illustrated in the accompanying drawing which shows in central longitudinal section an arnior-piercing pro- ]5 jectile in which my invention is employed.

\Vithin an armor-piercing projectile the shape of the cavity for contaunng the burster charge is standardized and conforms in a general way to the externalcontour of the shell, but is so shaped that the thickness of metal is greatest toward the point.' This is .shown In the drawing.

Of late years certain explosives have come into use, because of their relatively great explosive power, which at the same time are relatively sensitive to shock; such explosives are trinitrotoluene (commonly written for convenience, though not according to accepted chemical notation, T N T) and tetranitroanilin (T N A) and picric acid, and

others. These substances are so sensitive that, when used to fill the tapering chamber of a projectile. the shock of impact, when the flying projectile strikes heavy armorplate. is apt to cause premature explosionanticipating the operation of the delay-acting' fuse-mechanism provided to effect detonation.

\Vhen a flying projectile strikes and its 40 speed is checked, the body of explosive'mm terial within is caused to set forward and there is a consequent sudden enormous compression of the burster charge. The stresses of compression are concentrated at the tip of the forwardly tapering chamber; and it.

is at this point that premature explosion origmates.

It hasbeen proposed to fit into the peak,

that is, the anterior end of the cavity which receives the burster charge, a conical block of wood. By resorting to this expedient, the

shape of the shell is not altered and the disposition of metal is the same, but the body of burster charge, instead of being attenu- 5 ated to a pointy-is blunt in front and abuts upon an extended flat surface. With such a block of wood present the strains consequent upon striking armor-plate are not concen trated in the peak of the cavity and the danger of premature ignition is removed. But the body of wood is inert and occupies space which should be occupied by explosive, the efficiency of the burster charge is accordingly impaired, and the advantages which might otherwise be enjoyed in using such high explosives as have been mentioned are thus wholly or to a large extent offset by this disadvantage.

My invention consists in filling the cavity for the burster charge in the main with these high-power and desirable explosives but with this qualification: Before introducing the body of sensitiveexplosive, I fill the ably diminished; and at the same time the stress of compression incident to striking 1s concentrated, not in a body so sensitive as to be in danger of exploding prematurely, but in a relatively insensitive body, capable-of enduring the stress.

' In the accompanying drawing, the projectile is indicated at 1, the cavity for the burster' charge at 2. The contours shown are approximately those'now standardized.

Within the cavity is the body of explosive. The greater portion 3 of this body of explosive is of relatively high power and is relatively sensitive to shock, but at the anterior end of the cavity and .filling the peak thereof is the smaller portion 4: ofsomewhat inferior power but of appreciably less sensit-iveness to shock. The cavity is closed pos-.

teriorly with the base plug 5, which carries the detonating fuse 6, indicated in outline. I claim as my invention: '1. The combination within the forwardly tapered cavity of a projectile, of a body of relatively insensitive explosive capable of sustaining without explosion the stress of impact occupying the anterior end of the cavity and a body of a relatively sensitive highpower explosive filling the major portion of the cavity, to rearward of the body of explosive first mentioned substantially as described.

2 The combination, ithin the forwardly tapered cavity of a projectile, of a body of relatively sensitive high-power explosive, and a body of relatively insensitive explosive capable of sustaining Without explosion 10 the stress of impact occupying the tapered end of said cavity, substantially as described.

In testimony whereof I have hereunto set my hand.

JOHN B. SEMPLE. W'itnesses BAYARD H. CHRISTY, FRANCIS J. ToMAssoN. 

